The intervening spaces are concealed with layers of pumice, ashes and volcanic tuff.

This will build friendly calluses and harden your hands for granite and volcanic tuff.

The Punchbowl is an extinct volcanic tuff cone located smack in the city of Honolulu.

The visible land was of black or chocolate-brown, being composed of volcanic tuff, basalts, and granite.

These lines at regular intervals here," he continued, pointing further up, "these are volcanic tuff.

One distant day, these man-made caves-andeven natural ones, of stone much harder than volcanic tuff-willwear away.

The Catacombs are volcanic tuff similar to that of the Happies, but with a fraction of the traffic.

The soil is soft volcanic tuff and eons of erosion have sculpted the terrain into bizarre and breathtaking shapes.

While the main area features volcanic tuff, the Lower Gorge hosts rows of trad and sport routes on columnar basalt.

Precisely how it will go when climbers return to climbing nubby, runout volcanic tuff above the Crooked River remains uncertain.

The white cliffs, hoodoos and slot canyon are all made of of volcanic tuff that erupted around a million years ago.

Only the 45-minute approach and effort necessary to establish routes on Smith's notoriously soft, scruffy volcanic tuff limit the Marsupials' tremendous potential.

Calcata is older than Rome itself but was built on volcanic tuff, a light porous rock which becomes crumbly with heavy rainfalls.

The Paiute also carved petroglyphs into the volcanic tuff, creating lines, concentric circles, and ornate scenes at Sky Rock and other sites.

Though he climbs at local areas near his home a fair amount, Ruana visits the volcanic tuff of Smith more than any other climbing area.

Oregon volcanos had erupted a million years earlier, and combined with gas explosions, ash fall, and gravity, a series of volcanic tuff formations were created.