Airports of London cannot be expanded due to the docks on either side. It is also the only airport serving London which does not operate at night. A light rail service from London City Airport DLR station, which adjoins the terminal building of London City Airport, links it to the financial district of the City of London at Bank and Monument stations, which offer interchanges with London Underground. Located in the London Borough of Hillingdon, Heathrow is by far the largest of London's airports and considered the main gateway into the United Kingdom for non-European visitors. Heathrow has four terminals and two parallel
Özkonak Underground City the tunnels used for dumping hot oil on the enemy. Just like Kaymaklı and Derinkuyu, Özkonak has a water well, ventilation system, winery and moving stone doors. Özkonak Underground City Özkonak Underground City is an ancient city built into the northern slopes of Mt. Idis about 14 km northeast of Avanos in Nevşehir Province, in the Central Anatolia region of Turkey. The city has many strata made up of volcanic granite. Its larger areas are connected to each other by tunnels, and it contains a pipe communication system reaching each of its levels. This feature is unique when compared to