Dozens of perfectly preserved ancient shipwrecks have been found at the bottom of the Black Sea dating back as far as 2,500 years, including galleys from the Roman (top right), Byzantine (top left) and Ottoman empires, as well as the Medeival period (bottom left). Scientists accidentally discovered the graveyard while using underwater Remotely Operated Vehicles (bottom right) to study the effects of climate change along the Bulgarian coast. Because the Black Sea contains almost no light or oxygen, little life can survive, meaning the wrecks are in excellent condition. Carvings in the wood of some ships have remained intact for hundreds of years, while well-preserved rope was found aboard one Roman ship (top right)