Edit / Change Park Entrance

My apologies if this has been asked / answered before, but I have performed a forum search and couldn't locate the answer.

I started my very first park last night in Beta - so far, I'm really enjoying the game and it's customisation. However, one thing I note is that loads of people on YouTube etc have really elaborate park entrances...where as, I have...

How are being making these bigger? I'm probably missing something obvious, but...help?? [wacky]
If you click on that gate, there's a button on the dialog that opens to "Select Building". Click on that, then click the "edit building" button on the next screen (shaped like a pencil) and you can build round your entrance! You can place more of those ticket gates from the "Shops and facilities" tab.