Tortola Island, British virgin islands . Touristic Sight Discovery. Tortola (Spanish for Turtle Dove), largest and most populated of the four main Islands, is a lush mountainous Island which was formed by volcanic activity. Crowning Tortola is the tallest peak, Sage Mountain National Park, at (1716) feet, which exhibits the characteristics of a tropical rain forest. The Island has a population of (24,045) and 55.7 sq. km (21.5 sq. mi) in size. Tortola is also the vibrant hub of the financial and government sectors with Road Town "The Small Town with a Big Heart" as its capital. Road Town is home to the beautiful J R O Neal Botanic Gardens which features close to three acres of indigenous and exotic plants, trees and herbs. The capital is also filled with restaurants, shops, and is the site for the hospital, government administration offices and official Governor's House with its historical museum. Just behind Waterfront Drive is Main Street, a peep into the British virgin islands architectural past, which still has many historic buildings