All local residents whose ID card numbers end with '20' (excluding the bracket digit) will be admitted to Ocean Park free for the next two Saturdays. The offer follows on from the overwhelming success of the free admission promotion for all local 20-year-olds last month. Eligible residents must present their ID cards at the park's entrances. The offer is one of the many activities organised by Ocean Park to celebrate its 20th anniversary. Other celebration programmes under its '20 Years into Infinite Fun' campaign in the forthcoming months will include a scratch card contest next month, a grand luck draw and a photo competition in June. Since its opening in 1977, Ocean Park has hosted more than 44 million visitors, according to Florence Chan, Ocean Park's marketing communications manager.