Lava Beds National Monument

Pluto's Cave is 50 square miles of partially collapsed lava tubes on

Mount Shasta (Úytaahkoo, Karuk) or the 'White Mountain' in English, a

Burney Falls is a waterfall on Burney Creek, in McArthur-Burney Falls

Mossbrae Falls is a waterfall flowing into the Sacramento River, in

Hedge Creek Falls is a waterfall on hedge creek, in the Shasta Cascade

Castle Lake is a glacial lake (cirque lake or tarn) located in

Castle Crags is a dramatic and well-known feature in Northern

The Allen Telescope Array (ATA), formerly known as the One Hectare

The Ear of Dionysius (Italian: Orecchio di Dionisio) is an artificial

Hezekiah's Tunnel, or the Siloam Tunnel is a tunnel that was dug

The Lost River Reservation (also known as the Lost River Gorge &

Beer Quarry Caves is a man-made limestone underground complex located

The Balzi Rossi caves (Ligurian: baussi rossi 'red rocks') in