So, there's a fairly plain metal gate blocking off one of the two exits to the house's curved driveway, and if you walk your bike around that gate, it turns out there's a whole road back there! She leads him along it, and when it comes to a fork she goes right, and all told it is in fact longer than the ten minutes she promised it'd take to walk straight through the woods, but eventually they round a final curve and pass through another gate across the road (wrought iron and beautiful, screeching balefully as Rosy shoves it open far enough to admit them) and arrive at A Mansion.
The new house is already a mansion, but this mansion is bigger, and older. It has towers—two major ones, a big one on the mid-right and a smaller one peeking over the roof to the rear left, plus an assortment of little turrets placed decorously at various corners. Instead of a relatively modest portico it has an entire balcony overlooking the area in front of the house, flanked by two half-towers set into the front wall. Speaking of which, 'area in front of the house' is something of a misnomer, because besides the main house section with its several floors and two entire towers, there's also two huge wings, each almost the size of that main building, set off from it at forty-five degree angles like a pair of arms reaching out to embrace the front area.
The wing on the right has a huge gate that it looks like cars are meant to drive through, so maybe it's meant to be some sort of garage? It could eat four normal garages for breakfast. The wing on the left has a lovely colonnade situation going on, and a great big bay window on the second floor that looks like it probably gets a spectacular view of the paved area between those wings. The paved area is worth having a spectacular view of, because there's a huge multi-tiered fountain in the middle of it which, although currently full of dead leaves and mud, looks like it would be quite the spectacle if it was clean and working. Even the paving stones are pretty; all different shapes and sizes, they're arranged in a subtle gradient of lighter over here, darker over there, bluer and redder and yellower in various places. In the light of the afternoon sun it looks lovely.
The whole place is enclosed by a tall, rather overgrown hedge, which was clearly very imposing in its prime and is honestly even more imposing now that it hasn't had a haircut in decades. The only visible break in the hedge is where the two of them are standing, at the gate where the road comes in; it otherwise seems to encircle the house completely, though there might be a second gate behind the house and out of sight.
Rosy takes a deep breath, looking up at it all.
"Welcome to the old house. Do you want to leave your bike at the gate, or take it into the stable?"