Çatalca

One of the most rural districts of Istanbul Province, the lush countryside of Çatalca dotted by farms and agricultural land has little to suggest that you are just outside the urban behemoth of Istanbul.
As the ancient Ergiske and the Byzantine Metrai, the settlement in Çatalca dates back millenia ago, although most of the town centre is of modern constructions with few remains from this long past.
The recent history recorded Çatalca as the site of the Chataldja lines, the last defence line of Istanbul during the Balkan Wars of 1912–13, although the actual fortifications were centred in (the then village, now suburb of) Hadımköy further east towards Istanbul, and Çatalca was completely within the Bulgarian occupation zone (much of it being burnt down at the end of the occupation).

D-569 is the main highway that connects Çatalca with the rest of the world. It branches off D-100, the main highway heading west from Istanbul in Büyükçekmece (the signage on ramp is fairly small, so watch out for it); an exit from the motorway O-3/E-80 further north also connects with it.
The public bus line #401 departs from the Yenibosna station of Istanbul's M1A metro line, bringing the passengers in Çatalca's main square in an hour or so (5 TL).
Çatalca lies 2 km east of the town, but as of 2016, no trains serve this station due to high-speed rail constructions in the area.

The , complete with a park and a statue of the founder of the Turkish Republic, Kemal Atatürk, is in front of the district government building (Kaymakamlık). Anywhere in town is within walking distance from here. For the transport options to the rural attractions, see the "Go next" section below.
Finding a convenient parking space for your car in the centre might be a little hard some of the time.

• Old townBefore the collapse of the multinational Ottoman Empire, this used to be the Greek quarter of the town, and was spared from the destruction during the Bulgarian occupation of 1912–13. Stroll around its streets to see the historic wooden buildings (some are beautifully derelict), and ancient fountains in the middle of small squares overshadowed by old plane trees.

• Population Transfer Museum

  address: Bahar Sk 4
  Housed in a red brick neoclassical building erected as a Greek tavern, this museum commemorates the forced "population transfer" of 1922–26, under the conditions of which the Greeks of Turkey were expelled to Greece, while the Turks of Greece were expelled to Turkey. As the Greek population of Istanbul itself was exempted from this mutual exchange, and hence the city received no expellees from Greece in return, Çatalca is the closest location to Istanbul in which this took place.

• Ancient city wallsA short section of the ancient walls of the town, once enclosing the entire perimeter of the old town, still exists along the street heading north from the centre. Fans of the ancient walls will find the Anastasian Wall far to the northwest (see "Go next" below) much more fascinating, though.

The verdant countryside north of Çatalca features some of the least known attractions of the Greater Istanbul Region: the İnceğiz Caves (actually a Byzantine monastery carved onto a cliff), the Anastasian Wall, which was once the outermost defense of the Byzantine capital of Constantinople and is now lost in the forest, and various pleasant villages and beaches on the Black Sea.
Follow the highway D-569 north from Çatalca to get to these attractions — for the most part a scenic drive through a forested and hilly landscape — however getting to anywhere beyond the villages by public transport is not a realistic option.

İnceğiz

(İnceğiz Mağaraları) are actually a series of multi-floor and interconnected Byzantine-era monastery chambers carved onto a lush cliffside, overlooking a local stream. While there is no admission fee to the site itself, İspark, the carpark company affiliated with the Istanbul Metropolitan Municipality, charges a toll of 5 TL/car on the only road leading to it, during the high season (May–Sep). There is a couple of restaurants nearby.
The village of İnceğiz, 1 km north of the monastery, is served by minibuses departing from their stop in Çatalca, a block north of the central square. There is also a train station nearby, but as of 2016, no passenger trains serve the line.
A road from the village proper goes down to the caves, as well as a shortcut through the forest direct from the road from Çatalca before arriving at the village — drive slowly and watch for the signpost.

Further north — towards the Black Sea

From İnceğiz, return back to D-569, and follow the signs for Saray and Kırklareli as far as the village of . The forests near this village are dotted by unexpectedly well preserved Byzantine era aqueducts, which once formed part of a huge network that extended as far as to the water sources near Vize in Thrace to drench the thirst of the Byzantine capital of Constantinople. However, these ancient structures are almost impossible to locate unless you have a local guide with you. The local forests in the area are also the source of much charcoal — you will notice piles of wood (loda) ready to be "cooked" into charcoal here and there. The public bus #402 from the central square of Çatalca passes through the village. In a junction past Gümüşpınar, follow the signs for Karamandere and , which is one of the larger forest villages of the area. Save for a renovated historic building near the eastern end of the village, and the seemingly out of place quite frequent signposts for Belgrat (the Turkish spelling of Belgrade; this is a nearby village originally settled by immigrants from its namesake Serbian capital in the 16th century, also giving its name to the forest stretching from here to the outskirts of Istanbul) there is nothing of much interest here, although this is the last place to stock on supplies if you intend to have a picnic in the surrounding forests or to head for one of the undeveloped beaches nearby. The public bus #404 serves the village and departs from the central square of Çatalca.
From Karacaköy on, follow the signs for Yalıköy. After 5 km or so, follow the sign for Evcik Plajı to the right in a junction. This narrow road through the forest will take you to the Evcik Beach on the Black Sea, passing by some substantially preserved sections of the (Anastasius Suru), one of the most dramatic and surprisingly undervisited historic sights in the area.
Often compared to the much better known Hadrian's Wall of Britain in its timeframe and complexity, the Anastasian Wall or the Long Wall of Thrace was built (or probably strengthened) by and named after the Eastern Roman/Byzantine emperor Anastasius I (r. 491–518 CE) across the Çatalca Peninsula for some 56 km (35 mi) between the coasts of the Black Sea and the Sea of Marmara as the outermost defence line of the imperial capital complete with forts and towers, so that any army intruding to the narrow peninsula from the northwest wouldn't show up in a surprise attack just out of the city walls of Constantinople, which lies more than 60 km (40 mi) to the east. However, as later attacks on that city proved that the Long Wall was of limited effectiveness, it was abandoned in about two centuries after it was initially built. The time, nature, inhabitants of the nearby villages who reused the parts of the wall for their building projects as well as modern treasure hunters all have taken their toll on the wall, and all that remains in relatively good shape are some disconnected sections — of layers of huge stone-cut blocks up to high and a little less than that as wide — and the bases of some of its towers in the woodlands along the road leading to the Evcik Beach; elsewhere the remains of the wall are limited to seemingly random piles of rubble or mounds following an orderly direction through the farmlands, or are lost under modern developments altogether. The wall is not signposted from the modern roads, but it is unmissable once you are there.
Following the road on the side of the wall towards north, you will arrive at the Black Sea beach of , which is not a village and has no businesses of any kind. A nearby hill is topped by the ruins of a Byzantine era chapel, marking the northern end of the Anastasian Wall. In summer weekends, you will find the beach very crowded, with one side of the last part of the already narrow road descending into it as a virtual carpark. For a calmer, though not an altogether away-from-the-civilization beach experience, head back to the dirt road crossing to the outer (western) side of the Anastasian Wall through a breach on the wall. While there is a sign saying Yasaktır ("forbidden") erected by the Forest Ministry at the beginning of this road, it seems no one cares about it, and the road will take you to , again undeveloped, in about 10 minutes after some sharp descends and ascents — and a short section of extremely uneven surface that needs very, very careful driving — through a jungle-like forest. If only there were less plastic bags strewn about the pretty partially shingle, partially sandy beach.
Upon returning back to the main road leading from Karacaköy, you will soon arrive at the seaside village of , formerly known as Podima, Greek for "boot" presumably after a nearby cape. The village is the northwestern terminus of the public bus line #404 from Çatalca. A reasonable selection of restaurants exists along the village coast, along with accommodation options. Beachcombers will want to know that the beach of the village, and others nearby, are made of stones that are extremely varied in shapes and colours, and as such were the source for "Podima stones" (Podima taşı). Podima stones were extensively used in the mosaic tiles of Istanbul's gardens in olden times. This type of mineral extraction from the area has now been transformed to the much more destructive open pit silica sand mining in the surrounding forests, which feeds the Turkish glass industry.
West from Yalıköy (10 km) is the (12 TL/car daily use; 23 TL/car night stays), a nice sandy beach backed by lush cliffs.
Çilingoz marks the end of the range of any reasonable family car. However more adventurous souls with sufficiently sturdy vehicles may take the dirt mountain road leading west from here, following the coastline in a distance, past the (Korsan Koyu), a small and very isolated beach surrounded by rock cliffs, towards the relatively developed beach at . Otherwise, either take the forest track, reportedly in a better condition than the coastal road, south to Binkılıç (17 km), or to be completely on the safe side, simply return back to the highway D-020 at Gümüşpınar, and head west from there, going through a forest just as beautiful. This road will whisk you past just outside the village of , formerly a Greek village known as Istranca, giving its name to the mountain range extending along the Black Sea coast of Thrace, with some remarkable wooden architecture, including houses with bay windows atypical in the region. Binkılıç is the terminus of the public bus #402 from Çatalca. Past Binkılıç, the highway will eventually take you to Saray.
Away from the towns and the main roads, the GSM signal is weak or completely absent in the area.