The church is of 12th-century date and stands in the grounds of 15th century Eldon House (now Upper Eldon Farm). The structure is an incredibly simple single-cell affair, with just a nave and south door.
There is no bell turret or tower, and only a single, narrow lancet window on the south wall, with two further lancets on the north wall, an east window, and a west window. One odd feature is a square hole set into the west wall, possibly used by lepers to view the altar during services.
The entire building measures only 32 feet long and 16 feet wide.
One unusual feature is that there are nine consecration cross stones, each bearing an incised carving of a circle with five holes, and a further hole to the top of the circle. These holes are thought to have held iron consecration crosses from the dedication ceremony for the church.
St John's is no longer used for regular worship and is in the care of the Churches Conservation Trust.
Visiting
Eldon church is not easy to find, at least it wasn't easy for me! I used the official postcode for my satnav, which directed me down the narrow lane from Kings Somborne in the direction of Romsey. When I say the lane is narrow, I mean it is seriously narrow, with limited visibility and only a few scattered places to pass an oncoming vehicle.
The church is hidden by hedges at Eldon Farm, and I passed by it completely, and by the time I realised something was not right I was two miles down the lane, looking for a place to turn around.
There is a wide place opposite the farm driveway, but you can't really see the church unless you approach from the Romsey direction. There are no signs to the church that I could see from either direction.
The church is located within private grounds, but there is a right of way for pedestrians to walk across the carefully manicured lawn, past flower beds, to the south door of the church.
The church stands in a lovely rural setting and seeing it surrounded by the Eldon House gardens is a beautiful sight. The interior is plain and of very simple construction, and won't take long to explore. It really is an attractive, rural medieval church.
Since our visit we have been in communication with the owners of Elsdon House, who have asked us to request that visitors leave animals, bikes etc. outside and please do not wander around the garden, which is private property. Also, please do not use the grounds for picnicking or dog-walking.
If anyone is interested in an in-depth tour of the church this can be arranged by appointment with The Churches Conservation Trust.