Do not visit these areas. There have been terrorist attacks resulting in fatalities in Colombo. It is considered impolite to refuse the offer of tea. Punctuality is considered important. Arms and legs should be covered when visiting religious sites and shoes and hats must be removed.
Sea bathing is dangerous as there are strong riptides and undercurrents.
There are severe penalties for drug offences. Your Passport to Safer Travel gives practical tips and advice for travelling independently aroundthe world - safely.