Banff National Park
The most beautiful lakes I've ever come across. Canada's first national park should be on everyone's bucket list. It's easy to get to once you reach Calgary (you can get a direct flight from london). Summer is peak season and the lakes can be surrounded like a zoo with cars parked as far as 10km out so make sure to plan ahead and get there early in the morning.
I found each lake to have their own personality and colour, so take the time to explore each one. They also vary depending on the time of the day. Mornings are more for shooting reflections and afternoons are more for colour. Around each lake you can do small or long hikes which takes you higher up for better scenery. The hike from Lake Louise to the tea house was really good, not too long and when you reach the top, lovely teahouse awaits with cakes (but don't expect French elegant style, it's more the biscuits and tea type). Lake Moraine was my favourite lake. That beautiful blue colour and its scenic reflections. It's worth the trip to Banff just for this lake alone.
Hotel wise, I stayed at the Fairmont lake Louise chateau. It's huge, expensive, not worth the money but right on Lake Louise so easy to get up early for sunrise. It's better to rent a small cottage, better value plus it's easy to drive to everywhere. Food wise, if you are going from Europe, lower your expectations way down. It's very American, flatbread that turned up like a pizza, sandwiches loaded with bad mayo (yes you can get great mayo if it's made properly, as they say, with love and care) and soups salty enough to down a litre of water after. Even the famous Alberta beef was soso, didn't have much flavour to it (or maybe I didn't get the best one?!). This trip made me realise how spoiled I've been with great food in London. You can find decent restaurants in Calgary, great dim sum and French bistros so save food for the cities and just go Banff for the scenery!