2 February 2011
Last updated at 14:46
There is still a 30 km exclusion zone around the Chernobyl site.
The Chernobyl nuclear complex contained four reactors in total. The explosions on 26 April 1986 occurred in Reactor Number Four, at the end of the building closest to the camera.
Chernobyl's 'golden corridor' used to run the full length of all four reactors. On the left are the turbine halls, on the right the four reactors. The corridor now stops at the end of Reactor Number Three.
Part of the current construction work is to fire proof the destroyed reactor before sealing it off within the new sarcophagus. The melted reactor core is on the other side of the wall on the left.
Taking the first steps into the control room of Reactor Number Four. The room is unlit and your eyes need a moment to adjust before you see the outline of the control panels.
Chernobyl's Reactor Four control room is where staff had the first indications of a problem.
Radioactive dust particles cover every surface and fill the air of the control room.
Each light on the control board of Reactor Number Four represents a nuclear fuel or cooling rod. On the night of the disaster, these lights would have illuminated to indicate a problem in the reactor.
The control room of Chernobyl's Reactor Number Three is in a better condition. Although all the reactors are now shut down, people continue to work here.
Igor, shift supervisor for Reactor Three, says he misses operating the reactor.
The town of Pripyat was built in 1970 to house workers from the Chernobyl Nuclear Power Plant.
More than 50,000 people were living in Pripyat at the time of the disaster; it is now deserted.
Residents were given orders to evacuate the town 36 hours after the disaster; they were given just two hours to leave.
Residents of Pripyat thought they would be coming back when the town was safe; they never did.
"Every weekend we had discos in Pripyat. This is part of the electronic equipment used for the discos. It has a name on it. Edison 2. That was the name of the disco," says former resident Andrey Glukhov.
The cultural centre in Pripyat once provided a wealth of activities for the residents, including dancing, theatre and even an amateur radio club.
Reporter Richard Hollingham interviews a former resident while looking out over the children's amusement park. The park was never used, as it was due to open on May 1 1986.
Twenty-five years of freezing conditions have taken their toll on the town's buildings. All pictures by the BBC's Steven Duke.