Jerusalem’s burial society is plumbing new depths to devise funerary solutions to Israel’s shortage of space, and has broken ground on two experimental crypts near the entrance to the city.

The two 65-yard-long, 21-foot-high underground tunnels will be able to accommodate 300 bodies apiece once they’re completed in the coming three months, according to reports Sunday.

The innovative solution to Israel’s limited land area available for cemeteries taps into a millennia-old Jewish tradition of rock-cut tombs, such as those found at the Roman-era town of Beit She’arim near Haifa.

Approximately 35,000 Jews are buried each year in Israel, a tenth of whom are interred in Jerusalem, a Haaretz report said.

The head of the Jerusalem burial society said that there is no Jewish legal restriction barring burial in such tunnels, making it permissible to Orthodox groups that question the validity of burial in Israel’s multi-story tombs.

He said that 22,000 additional graves planned for Jerusalem’s sprawling Har Hamenuhot cemetery in the long term will be constructed below ground.