Sri Lanka is a seriously verdant island. You will be blown away by how green it is, not to mention the abundance of wildlife.
Another gem in the crown of Sri Lanka are the railways. We took a train from Colombo to Kandy on arrival, but the two train rides that stuck in the mind were from Kandy to Nuwara Eliya, then from here onwards to Ella.
Some of the more Instagrammable routes book up early, so best to sort tickets a couple of days in advance when possible. We rode all classes – but definitely best to shoot for 2nd or 3rd.