Rainbows End is on Ramsey Island. It's detached, but the main living area is upstairs. That's why they call it an upside down house. You get the views from up there, across the river and out to sea.
It sleeps four. Two bedrooms downstairs, both doubles. One bathroom with a shower. It's got a 4 Star rating, so it's well kitted out.
The stairs to the upstairs living room are the main thing to know about. They're open-tread and a bit steep. Just take your time.
You're right by the River Blackwater. The beach is about 50 yards away. There's a shop and a pub about half a mile down the road. The pub does food.
Maldon is close by. Good for a wander, and you can see the Thames sailing barges at the Hythe. Promenade Park there is good if you've got kids, with a playground and a splash park.
Burnham-on-Crouch is about five miles away. It's a sailing town. There are a few places to eat along the quay and a small cinema.
For a day out, Stow Maries Aerodrome is worth a visit if you're interested in old planes. It's about ten miles. The Essex Coast is good for walking. You can drive into Suffolk or up towards Colchester within half an hour.
The house has a washing machine, dishwasher, WiFi, and parking. There's an enclosed garden with a BBQ. Bedding and towels are included. Sorry, no pets.
Useful links: National Trust Essex and Visit Essex.