Andrew
Google
First things:
Go through the main archway, just off to the left of Kandy Road at Dragon Junction-East, along the road to the visitor centre where you can purchase the entrance ticket. There is only ONE ticket office despite 2 other entrances! Do not start at the Golden Buddha statue otherwise it is a very loooong walk to the ticket office, with even more stairs. Entry to the caves costs SLR 3000 per person. Pay the exact amount otherwise you will be told there is no change and he'll try to keep your money, despite a visible wad of cash in hand. Honestly!
There is a carpark next to the Golden Buddha (cannot park inside) and you will be charged per car/motorbike. But be prepared for a loooong walk from here. Do not be conned by any tuktuk drivers who will want to take you places and charge you a fortune.
Do not wear shorts at the cave temple (even long shorts that cover the knees, irrespective of gender) otherwise you will be made to hire a cloth for SLR 100. Good grief! Long trousers or skirts are a must.
You have to hand in your shoes (they are fussy about putting your shoes in your backpack) and they will insist on money but this is not mandatory. You can just walk away.
It is a sweaty climb up to the cave temple. Carry water and if it is sunny, wear a hat. Also, the caverns are small and not cool.
The main event:
What incredible sights inside the 4 caverns! The various Buddha statues, small stupas and extensive rock paintings are astonishing. Guides are on hand to explain, even if you do not choose a guide. Furthermore, there is a painstaking restoration (fairly unobtrusive) going on and it is so interesting watching the work.
There are other cave temples around Kandy and Matale which are similar and considerably smaller in scale, charging SLR 500-1000 person. So yes, if this is your thing, it is worth the effort and climb the see the Dambulla Caves. But be savvy!