To help me remember where I've been, along my 60+ years of travels, I have amassed a decent collection of rocks, pebbles, bits of bark — in addition to my 20,000 slides. On the floor of this extraordinary Jain temple in northwestern India, a tiny fragment of marble was waiting for me to pick it up. It's been perched in a prominent spot in my living room ever since.

See more slides from My Grand-Père's World.