Why did they choose to name galapagos island that?

Answer 1

The name was given by the Spaniards back in the 16th century. A Bishop named Tomas de Berlanga after reporting great tortoises that looked like saddles, to King Charles V of Spain, the Islands were baptized with the name of Galapagos that means saddle.

Answer 2

The name "Galapagos" is inspired by the Spanish word for tortoise, "galápago." The islands were named by Spanish explorers who were struck by the abundance of giant tortoises they found there.