The Diana, Princess of Wales Memorial Fountain is closing for four months while work to improve it takes place.
Last year the fountain attracted up to 5,000 people per hour
The fountain, which opened in July last year, has suffered a number of setbacks including closure after visitors were hurt when they slipped on it.
Turf worn away by visitors will be replaced with tougher grass, a path extended and a better drainage system installed after problems with flooding.
The Royal Parks say the fountain, in Hyde Park, will reopened by 1 May.
The turf will be replaced with tougher rye grass which is normally used on sports fields.
It is hoped it will be able to cope with the high number of visitors the fountain attracted last summer - up to 5,000 per hour.
The path will be extended to run around the south and west of the fountain to ease pressure on the grass in these areas.
Drainage systems aim to help the area cope with extreme wet weather.
Greg McErlean, head of Major Projects, said: "This is the first practical opportunity we have had to do this important work.
"The Memorial has had its problems in the last six months but this work will ensure that it is truly a special place of relaxation and remembrance for years to come."