Tour highlights include the Roman city of Dougga, the underground Numidian capital at Bulla Regia, Roman Sbeitla and the remote areas around Tataouine and Matmata, uique for underground cities.

旅游亮点包括罗马的杜嘉城，位于布拉雷加的 Numidian 地下首都，Roman Sbeitla，以及塔塔旺和 Matmata 周围的偏远地区，这些都是地下城市。

youdao

The USA, China, and Russia have massive underground cities all over the world.

美国，中国，俄罗斯有巨大的地下世界各地城市。

youdao

Mount Weather, Virginia, and Raven Rock, Pennsylvania, have been compared to small underground cities.

弗吉尼亚的Mount Weather和宾夕法尼亚的雷文洛克山，都被比作小型地下城市。

youdao

To bypass the tour groups, visit the churches and underground cities early in the morning, at midday or near closing.

BBC: Turkey��s land of fairy chimneys

More to the point, if science fiction is any guide, building underground cities is usually a bad idea.

FORBES: Underground Living is a Solution in Search of a Problem

Millions of people travel on underground urban transit systems in cities across the world.

BBC: Railway tracks