The Israeli Defense Forces (IDF) revealed footage on Monday of a tunnel in southern Gaza, where Hamas is believed to have held Israeli hostages.

The tunnel, beneath the southern Gazan city of Khan Younis, had extensive facilities, including bathrooms. Israel says it destroyed the tunnel after completing its investigation.

‘The tunnel was located in the heart of a civilian area in Khan Yunis, and the entrance to it was located in the residence of a Hamas terrorist. According to intelligence estimates, millions of shekels were invested in the construction of the tunnel,’ the IDF said.

Shekels are worth just over one fourth of a U.S. dollar.

‘As part of the examination of the tunnel, a central chamber where hostages were held and five barred prison cells were discovered. In addition, the soldiers located findings that indicated that hostages had been held there, intelligence and weapons belonging to the Hamas terrorist organization,’ the IDF added.

While Israel is in control of most of the territory in northern and southern Gaza, Hamas remains able to operate thanks to its extensive network of tunnels.

Israel has cleared, bombed and even flooded tunnels throughout the region.

Top Hamas commanders, like Yahya Sinwar, remain held up in the labyrinth. Recent reports have suggested that Israel knows Sinwar’s location but has not attacked him because he surrounds himself with Israeli hostages.

Israel believes some 130 hostages remain in Hamas custody in Gaza, though it is unclear how many of those remain alive.