The clues for today's Geo Quiz come courtesy of Mark Twain. Back in the 1890's, the great American writer ventured a long way from the Mississippi. He was traveling around the world. One of his adventures took him up to the foothills of the Himalayas on a train.

The 40 mile trip took eight hours. But -- Twain wrote -- it was:

“So wild and interesting and exciting and enchanting that it ought to take a week....it was the most enjoyable day I have spent on earth.”

Twain was especially taken by the view.

“We were well up in the region of the clouds, and from that breezy height we looked down and afar over a wonderful picture-the Plains of India, stretching to the horizon, soft and fair, level as a floor, shimmering with heat, mottled with cloud-shadows, and cloven with shining rivers.”

We're looking for the name of the Indian railway line that Twain rode on. Its nickname is the "Iron Sherpa."

We'll take a ride on the historic train...