Splendid!  Just an extremely well-tended and well-curated garden that you can spend several hours wending through, and for free.  The glass houses are not free but are worth the extra poundage--each little ecosystem is almost magical in its transformation from the immediate outside surroundings.  Can't believe it's taken so many visits to Edinburgh to finally visit here--this is an excellent counterbalance to all that history and architecture, especially as many of the other EDI parks are either 1. private 2. filled with scary drunks or 3. on a big hill that is difficult to scale when pregnant.