Shfela

• Beit Shemeshthe modern day city was founded in 1950, although settlement has been on the site since pre-Biblical periods

• Modiina relatively new Israeli city, planned to be the fourth largest of the country within a few years

• Beth Guvrina chain of caves which was used for various purposes in ancient times. It includes colombariums, frescoes and other remains

The Shfela is characterized by fertile pastoral hills checkered with ancient ruins. There are also many small natural springs, often diverted into ancient stone pools. A popular hobby of Israeli teenagers is to repair and clean these pools or even build completely new ones. Israeli city dwellers go to these pools to relax and cool off during the summer, and during the weekends its rare to be alone in those springs for a long amount of time. Its also common to see "chill out" zones and fruit trees (especially figs and raspberries) near those springs.

The Shfela was an important region during biblical times. It is the gateway to Jerusalem and other big cities in the mountains, such as Hebron and Bethlehem, and there were many important cities in the Shfela itself, such as Beit Shemesh and Gezer.
It was also the main battleground between the Israelites, who sat in the mountains, and their arch enemies the Philistines, a Greek nation that invaded from the sea and conquered the coastal plains of Israel. One of the most famous battles in the world, the battle between David and Goliath, took place in Valley of Elah, one of two main valleys in the Shfela (along with the Ayalon valley). A couple centuries earlier, the Ayalon valley is where Joshua, according to the Bible, defeated the Canaanites by stopping the sun's movement.
When the Jewish leader Bar Kochba rebelled against Roman rule in the year 132, his followers built a network of caves across the Shfela (and to a lesser extent in other parts of Israel) to conceal them. These caves are still visible around the region (though it's not recommended to enter them without a guide who knows which are safe and interesting).
During Israel's 1948 war of independence, the Shfela was the main battleground between Israeli forces, who tried to break the road to Jerusalem, and the armies of Jordan and Iraq, who tried to reach the coastal plains and conquer the temporary capital of Israel, Tel Aviv. In the end, the line of truce between Israel and Jordan passed mostly through the Shfela. During the Six-Day War in 1967, all of the western bank of the Jordan river was conquered by Israel, including the Jordanian Shfela and the mountains of Judea and Samaria.

By train

• Modi'in Merkaz train stationTrains from here connect Modi'in to Nahariya via Ben Gurion Airport, Tel Aviv and Haifa. (A second station, "Paatey Modi'in", is on the city outskirts and of no interest to tourists.)

• Beit Shemesh railway stationThis station sees roughly hourly service towards Tel Aviv and hourly or two hourly service in the direction of Jerusalem

The Shfela has beautiful views of the coastal plains from one side and the mountains of Judea and Samaria on the other side. Probably everywhere you will go you will have beautiful views.
As a central place in Israel since the days of the bible, the Shfela has many marked trail routes that crosses the hills and valleys, while passing by springs and ruins. There isn't any organized reserve to pay and walk in a specific route. To travel here, you need to get a map of the area or to know exactly where your route starts, get there, and just start walking.
Like in the rest of Israel, each official trail is marked with 3 different colors, and you simply need to follow those 3 colors as they appear on rocks and trees throughout the route and tell you in which direction to go.
Several sites are adjacent to Latrun. If coming by bus, many routes from Jerusalem stop here. From Tel Aviv, your best bet may be to change buses in Ramla.

• Yad LaShiryonMuseum of old IDF tanks and captured enemy tanks, located in Latrun. Good fun for boys.

• Mini IsraelFeatures more than 350 replica models of historical, religious, archaeological and modern sites in Israel. While once a popular destination, it is now reported to be somewhat run-down, and not worth the price.

The Shfela is very safe to travel in. Car theft is known to occur, though less commonly than in the Negev desert.
If you plan to cross the Green Line into the West Bank, you should coordinate your trip with the Israeli army, and hire an armed medic to go along with you. If you are going on a guided tour with another group, they will probably hire the medic and coordinate the trip for you. It is hard to cross the Green Line by accident nowadays, as a security fence has been built along most of it.