Kolektory (literally Collectors) is the Czech name for the service tunnels that route major cables and pipes beneath the city of Prague. This then means that inspections, repairs and upgrades can be achieved without digging up the streets as in most other major cities. Services carried in this way include water (hot and cold), gas, electricity, phone and data. Although a small network existed earlier, the majority of the network was built in the 1980s and the total length of the system is over 90 kilometres.
Some of the larger tunnels are equipped with a narrow gauge railway to transport both materials and personnel. The network is on different levels, linked by ladder access for engineers. A small part of the tunnels were built by cut-and-cover but the majority was bored at a depth of up to 35 metres. Owned by the City of Prague, organised tours can be pre-booked which include a visit to the central monitoring room.