The most famous National Hunt race is the Grand National, run at Aintree in April each year. The race is a different sort of contest from the Gold Cup: it is a Grade 3 race, it is run over a distance of more than , there are up to 40 runners, the course at Aintree is essentially flat, and the horses are handicapped (the best horses carry the most weight). Perhaps the most fundamental difference is that the Grand National fences are far bigger than the fences at Cheltenham, and a number of fences incorporate significant drops. The most famous fence is Becher's Brook which is high, but has a drop on landing and is widely regarded as the biggest challenge on the course.