In the dark, the new mirror looked like an underground tunnel.

Through an underground tunnel, it will travel the city from east to west.

The two share a staff and will soon be connected by an underground tunnel.

They came to an underground tunnel, where a small electric car was waiting for them.

I took off for the track, half a mile away through an underground tunnel.

Both buildings have two stories and are connected by an underground tunnel.

The two facilities are connected to each other by an underground tunnel.

Visitors enter the work outside the park and continue through an underground tunnel.

I would just help you to find your way in the underground tunnels.

There are also underground tunnels that were once used to transport difficult patients.