Santorini is a crescent-shaped volcanic island in the southern Aegean Sea, part of the Cyclades group roughly 200 km southeast of mainland Greece. The island's dramatic silhouette - steep caldera cliffs dropping 300 metres to the sea, capped by whitewashed villages - is the result of one of the largest volcanic eruptions in recorded history, the Minoan eruption around 1600 BCE. That cataclysm collapsed the island's centre, creating the flooded caldera that defines Santorini's geography today.

The island's official name is Thira, though everyone uses Santorini. Around 15,500 people live here year-round, but that number swells to tens of thousands daily between May and October. The main settlements line the caldera rim: Fira (the capital), Oia (famous for sunsets), Imerovigli (the highest point), and Firostefani. The eastern and southern coasts are flatter, with black-sand and red-sand beaches, vineyards, and the archaeological site at Akrotiri.

Santorini National Airport (JTR) handles domestic flights from Athens (45 min) and seasonal European routes. Ferries from Piraeus port in Athens take 5-8 hours (conventional) or 2-2.5 hours (high-speed catamaran). On-island transport relies on KTEL buses running between Fira, Oia, Akrotiri, Perissa, and Kamari. Most visitors rent a car or ATV - roads are narrow but distances are short (the island is only 18 km long). Fira's central bus station is the main hub for all routes.