A road bicycle race, which starts in the city of Liege, Belgium, goes to Bastogne, and, surprisingly, back to Liege. It is usually held middle to late April. If you speak Flemish, you may prefer to call the race Luik-Bastenaken-Luik. It's one of the cycling World Cup races, and is nicknamed La Doyenne, because it is the oldest race in the series (first held 1892).
It is quite a hilly race compared to other races held near the same time, such as Paris-Roubaix or Fleche Wallonne. It also features cobbles, but not as much as Paris-Roubaix or Tour of Flanders.
The record for the most number of victories in Liege-Bastogne-Liege (LBL for short) is held by Eddy Merckx, who won it in 1969, 1971, 1972, 1973, and 1975.
Info from www.cyclingnews.com.