The child-friendly feature is only fair, given that the rest of the stunning £695,000 house is very much for the adults.
"The property offers ample period features throughout with a modern twist and has had no expense spared in bringing the internal conditions up to a very complementary level," say agents McEwan Fraser Legal.
It has seven - yes, seven - reception rooms and five bathrooms, split between the main house, a granny annexe and a separate cottage. It could be ideal for holiday lets, the agents say.
Indoor slides have also been installed at several company offices, including Liftshare in Norwich and the Workshop offices in Folkestone, Kent. The Electric Works office complex in Sheffield has even gone one better, by installing a 40-foot-high helter-skelter. Designer Toby Hyam said it was intended as a 'statement about risk-taking'.
Choo choo! This railway station house, near Welshpool, has lovely views over the surrounding countryside. It's currently laid out with a kitchen/breakfast room, sitting room and bedroom on the ground floor with a living room, bedroom and bathroom on the first. Outside is a two-storey signal box with power and lighting. It costs £225,000 from agent McCartneys.
It's tucked underground like an animal's lair, and has the name to match: Walnut Burrow. Near Rickmansworth, the four-bedroom eco-house boasts a cinema room and bespoke German kitchen. It's built around a central courtyard with a spiral staircase to the garden on the roof. It costs £2 million through agent Savills.
This sweet little toll house in Berwick-Upon-Tweed is small but perfectly formed, with just a hallway, living room, kitchen, bedroom and bathroom. Outside, there's just space for two small flowerbeds. But the rooms are large and bright, and the price is great - just £129,950 through agent Rettie.
This Yorkshire bungalow looks conventional enough at first glance, but it's actually built from straw bales - "well insulated and cosy," say the agents. It consists of a lounge area with wood burning stove, kitchen area, two bedrooms and bathroom. There's room for extension and outline planning permission for a further two-bedroom bungalow. Near Driffield, it costs £169,950 from agents D Dunk Lewis & Graves.
Once the control tower for RAF Wainfleet, this building near Boston, Lincolnshire currently looks rather forbidding - but could transform into a house of which the Thunderbirds would be proud. It consists of a four storey control tower, along with four detached buildings which once served as kitchen, rest room, gym and offices. The owners are looking for £300,000 to £350,000 through agents William H Brown.
This extraordinary apartment in Manchester takes up the clock tower of St Georges Church and spans nine - yes, nine - different levels. Fortunately, there's a lift. It has three/four bedrooms, three receptions rooms, a gym, sauna and roof terrace (with battlements) and is stuffed full of interesting architectural features including stained glass windows. It costs £1 million through agents Jordan Fishwick.
This one-bedroom cottage near Papa Westray, Orkney, is perfect for anyone that really wants to get away from it all. It has beautiful sea views from its 11 acres, along with a couple of outbuildings. Inside, it's been modernised and has wood floors and a wood-burning stove. Lows Solicitors are looking for offers over £90,000.
More of a Tardis than a boat, this 78-foot Dutch barge comprises a 24-foot reception room, separate, well-fitted kitchen and utility area and two good-sized en-suite bedrooms. It's moored at London's St Katharine Docks, where mooring fees are £14,312 a year. It's being sold through Riverhomes for £220,000.
The Addams family would love this eight-bedroom Gothic mansion in Crystal Palace, south-east London. It's packed full of original features, from elaborate architraves and windows to an ornate staircase and a belvedere. Amazingly, the attic space has been transformed into a mock-up of a spaceship for children. It's available through Hamptons International for £3,250,000.
This tiny but delightful cottage in Cornwall is packed full of original features: stone floors, beams, old doors - the lot. It's one bedroom is a double, and there's a small courtyard garden at the rear. It costs £159,950 through agents Bond Oxborough Phillips.