Pili or old Porta means Gate in english. Pili is located at the entrance of the lowland region of Thessaly in the mountains of Pindos. The two facing mountains: Koziakas and Itamos separated by Portaikos river forming a natural majestic gate, whence the name of the town. Gate separates from the settlement of Porta Panagia by Portaikos river.  Pili is interest to the visitors, because it is the center of important Byzantine and post-Byzantine monuments, but also because it is a passage for its picturesque villages Aspropotamos.
In place of settlement – Porta Panagia was the Byzantine city Megalai Pylai or Porta Panagia, which was called the Ottoman Porta - Bazar. The English traveler WM Leak, who passed through in 1810, refers to it as Upper Porta or Porta Panagia, in contrast to the new side of the Porta, which had been developed on the right bank of the river Portaikos and mentions him as Lower Porta or Porta - Nicholas. Both names Pili and Porta (Gate and Door) related to the geographical position of the town. In the neighborhood of Porta Panagia - born bishop of Larissa Bessarion II (1490-1540) who was declared a saint and protector of Trikala, Kalambaka and Porta. Pili was often serious field battles because of its position. Repeatedly destroyed by the invaders. Last time I was burned by the Italian troops on June 8, 1943.
The monuments are Bridges
At Portaikos river, at the height of the Pili, there are close to each other, four bridges different seasons (1514 to 1981) and different technique (stone arched, two of concrete, hanging).

1. The arched bridge located about 1 km west of the Pili and was built in 1514 by St. Bessarion. This bridge was unique in 1936, which connected the valley with Aspropotamos. It is arched with length 67 m, width 2.05 m, maximum height of 30.50 m and 0.70 m height barriers.

2. The bridge funds, needs of the time led to the construction of a new bridge on the carriageway linking Trikala mountain villages. So 1 km west of the old arched bridge built a new, modern for that time, concrete. The construction started in November 1934 and ended in June 1936. This bridge, like the shuttle, has a length of 45.30 meters, a width of 6 meters and 22 meters high. On 9 June 1943, the rebels, to prevent motor occupation troops, blew the left of the podium. The bridge dropped without breaking. Later sat up and restored to its original position, where it remains until today and serves the communication with the villages of Pindos and Arta.

3. The bridge Gikas, built in 1960-61 by reinforced concrete and serves until today many villages at the foot of Koziakas. Its length is 170 m

4. A hanging bridge, built in 1981 to serve the residents of Byzantine church . Its length is 120 m, and is based on two pillars of 6 m high. The suspension deck is blazing with straight wires and is the first bridge in Greece built with this technique. The width is 2 m and the height from the riverbed 7m.
Our Lady of the Great Gate (Porta Panagia)
Opposite Pili, in the settlement of Porta Panagia is the homonym Byzantine church, which formerly constituted the monastery church Stavropegic which brought the name Panagia. This was dissolved during the Turkish occupation. The church was built in 1283 by sebastokrator John Angelos Komnenos Doukas, the illegitimate son of the despot of Epirus Michael II Doukas. It consists of nave and later (for other earlier) porch.
The Monastery of the Dormition Gouras
It is feminine, built over Pili on Mount Itamos at an altitude of 640 meters. The view from the monastery is unique. The monastery was founded in 1743. Looted or burned by repeatedly (1770, 1823, 1854, 1878, 1943). Its present form began to take in 1961.
The Forts in Itamos mountain
Two peaks of the mountain -forest, SW of Pili, the ruins of two fortresses Greek times. Since they controlled all the passes of Agrafon and Pindos. These forts were occupied by Philip V of Macedon in 189 BC and destroyed by Julius Caesar in 46 BC In this region placed the ancient city Athenaeum.