Two highly catastrophic events occurred in 2018 in Indonesia. On 28 September a Mw 7.5 local earthquake near nprthwestern Sulawesi Island caused a strong tsunami that destructively affected Palu Bay. The earthquake and tsunami killed 4340 people, mostly in the area of this bay. Three months later, on 22 December an explosion of Anak/Krakatau Volcano in Sunda Strait between Jawa and Sumatra islands generated tsunami waves that killed 426 and injured more than 14,000 people. The book includes 22 scientific papers that thoroughly examine these two events. The papers include the results of comprehensive field surveys, source analysis, numerical modelling and detailed description of the wave effects on buildings and coastal infrastructure.