Are they Aesculus carnea? I remember seeing them on some scenes. Do you remember which season and episode? A screenshot would help.

I tried a screenshot but It wouldnt let me. The very beginning of season 3 ep 6 shows one pretty good

And yes the name you mentioned looks like a dead ringer. Good eye!

I've never watched the programme since it changed channels but red horse chestnut is a pretty common tree over here. If they look like it they almost certainly are since there's nothing else I can think of growing here that looks like them. These are in one of my local parks.

Personally, I like the white ones better. They're just so BIG and the leaves are better shaped.

We also see quite a few Aesculus indica which is another beauty.

Wow! Yes those look like it. So interesting to see things on another side of the world.

I was just doing the same frustrating google search - so glad to find this post!

Anyone know what this tree is please from GBBO?

Sierra redwood

I think sequoia, but that is why I started googling trees of

This webpage has photos of three "redwoods" on the grounds of Down Hall (GBBO venue for the current season) - two sequoias and one coast redwood. Looks like a pretty good match to the trees in this aerial shot.

Here's another question. Same show. What are these flowers? (S06e06 around 9:50)

Frittalaria

Id love to find a plant list for the gardens flanking the stairs…I keep zooming and have identified a few