Given the task definition and input, reply with output. This task is about reading the given passage and construct a question about the information present in the passage. Construct a question in such a way that (i) it is unambiguous, (ii) it is answerable from the passage, (iii) its answer is unique (iv) its answer is a continuous text span from the paragraph. Avoid creating questions that (i) can be answered correctly without actually understanding the paragraph and (ii) uses same words or phrases given in the passage.

Close to Richmond Park is Kew Gardens which has the world's largest collection of living plants. In 2003, the gardens were put on the UNESCO list of World Heritage Sites. There are also numerous parks administered by London's borough Councils, including Victoria Park in the East End and Battersea Park in the centre. Some more informal, semi-natural open spaces also exist, including the 320-hectare (790-acre) Hampstead Heath of North London, and Epping Forest, which covers 2,476 hectares (6,118.32 acres) in the east. Both are controlled by the City of London Corporation. Hampstead Heath incorporates Kenwood House, the former stately home and a popular location in the summer months where classical musical concerts are held by the lake, attracting thousands of people every weekend to enjoy the music, scenery and fireworks. Epping Forest is a popular venue for various outdoor activities, including mountain biking, walking, horse riding, golf, angling, and orienteering.
What famous London gardens were named as a World Heritage Site by UNESCO in 2003?