There is good diving and snorkelling off Bali (Nusa Dua, Sanur, Padangbai), between Komodo and Labuhanbajo in Flores, around the Banda Islands and off Pulau Biak off the north coast of Irian Jaya. The sea gardens of Sulawesi, particularly around Manado, are legendary. Renowned surf spots include Ulu Watu in Bali, Grajagan in Java and Nias off Sumatra, but there is surf along the southern coast of virtually all the islands in Nusa Tenggara. Windsurfing enthusiasts are well catered for in the southern resorts of Bali. Rafting is a new activity now offered on Bali's Ayung River.
Sumatra has good jungle treks, particularly in Gunung Leuser National Park. Berastagi and Bukit Lawang are also popular trekking centres in Sumatra. More adventurous jungle trekking opportunities are available in Kalimantan and Irian Jaya. For those who want to reach for the skies, Mt Bromo in Java and Agung in Bali are day climbs; Gunung Rinjani, the volcano that dominates Lombok, is a strenuous but worthwhile three-day jaunt.