The henge and the stone circles are thought to date from about 2500 BC to 2000 BC and are roughly contemporary with the more famous Stonehenge 20 mi to the south. The circular bank and ditch, which is almost a mile in circumference, encloses a much later mediaeval village, with a Saxon church and Elizabethan country manor. Many of the stones are missing or buried. Having been considered evil by the local farmers during mediaeval times, they were toppled or broken up, many of which to be revealed and restored in the 1930s by the famous archaeologist Alexander Keiller.
The village and henge lie at the centre of one of the most exciting megalithic landscapes in the world, with the remains of two prehistoric processional avenues of stones leading from the circle, leading to other nearby prehistoric points of interest such as West Kennett Long Barrow and Silbury Hill.
Avebury lies at the heart of the Wiltshire Downs, accessible easily from the M4 motorway, and is located about 6 miles west of Marlborough, along the A4 (Bath Road) at the junction of the A4361 and the B4003. Local signposting directs visitors to the official tourist car park which is situated just south of the circle itself off the A4361. There is a local village car park located in the centre of the village, but this has restricted parking for non-residents during daylight hours. The Red Lion pub in the centre of town has parking, so you might be able to visit it for lunch or a drink, then take a walk around.
Swindon, as well as being on the main line to London, has a good selection of local bus transport, and local buses which pass Avebury on their routes include Stagecoach in Swindon/First 49 Swindon-Trowbridge; Wilts & Dorset 5, 6 Salisbury-Swindon.
The village of Avebury can be best explored on foot, though access to the henge itself requires some climbing and walking over rough grassland and may not be suitable for all. Apart from the driest seasons of the year, it is advisable to have waterproof shoes or walking boots, since the grass can be wet and muddy, and the exposed chalk on the slopes of the henge can become slippery when wet. Two roads bisect Avebury, splitting the massive circle into 4 'quadrants' and each quadrant is fenced separately with sprung gated access.
In some seasons, parts of the henge may be roped off to prevent erosion, so please observe the signs and help keep this monument for future generations. At certain times of the year, one or more quadrants may have sheep grazing the grass and care should be taken to avoid letting any out, and dogs should be kept on a leash. The east-west road is the village High Street to the west and Green Lane to the east and is generally much quieter to cross than the main north-south road which is unfortunately the main road to Swindon and thus carries a fair amount of fast moving and heavy goods traffic. This main road takes a double hairpin bend at the centre of the circle, where it joins the High Street, and much care should be taken in this area. It is possible to walk to the other related local sights which make up the Avebury landscape, but in less favourable weather, car transport is advisable.
The henge itself is the main attraction of Avebury and each of the four quadrants can be visited one after the other in a single circuit of the circle. Many people prefer to go around twice, once close to the stones, and once right up on top of the henge bank, where there is a good path.
South West Quadrant
From just west of the Henge Shop on the High Street, you can enter the south west quadrant through the sprung gate and are immediately presented with an impressive arc of re-erected stones, starting with the misshapen 'blacksmiths' stone - this one was located by Keiller in the cellar of a blacksmiths where a 17th century antiquarian had noted it being toppled and used as building material. The 6th stone in from the road is the famous Barber Stone - when Keiller lifted this stone in the 1930s, the skeleton of a mediaeval Barber-Surgeon, with an intact pair of scissors, was revealed underneath, crushed by the falling stone.
South East Quadrant
After crossing the busy main road which goes south out of the village, the path leads you directly to one of the largest stones in the complex (about 60 tonnes) - the Devil's Chair - which has a small ledge on the outside edge where you can sit and make a wish. This quadrant also contains the remains of the inner stone circle and a central marker stone erected by Keiller to take the place of a much larger obelisk which stood there until the 17th century. At the exit of this quadrant, there is a huge sprawling beech tree on the henge, which reputedly JRR Tolkein used to sit under, and the exposed root system is certainly very Middle Earth.
North East Quadrant
Crossing Green Lane into the north east quadrant, there are very few stones revealed in this sector, mostly because Keiller ran out of money and this area was never excavated - you can be sure that many stones lie undiscovered under the grass. This sector does, however, contain the Cove stones, which are two huge flat stones perpendicular to each other - a third long lost stone once formed a three-sided 'cove'. It is interesting to note that while one of the stones is smooth, the other is very rough.
North West Quadrant
Crossing the busy main road into the north west quadrant, this sector is once again heavily reconstructed and as well as another impressive arc of re-erected stones, contains the single largest stone of the site - the Swindon Stone, which marks the way to Swindon. The exit from this quadrant leads you out to the courtyard where the Barn Museum, Tea Room, WC facilities, the Keiller Museum, St. James Church, and Avebury Manor gardens are all situated.
Other Avebury Sights
There are several shops in the village, as well as souvenir shops in the museums.
The Red Lion pub serves a wide menu of meals and snacks in its two indoor restaurants, and is open all day. The pub has bench tables out in front which can be pleasant to drink at in summer, but are too close to the busy road to make eating pleasant.
The tea room located in the courtyard beside the Great Barn Museum is open seasonally and sells sandwiches, buiscuits and teas, and has an indoor and outdoor seating area.
Many of the houses in Avebury village offer B&B accommodation.
Avebury is on the way to many interesting sites and can easily be visited on the same day as Stonehenge or Bath or Salisbury or Winchester for example. All of these locations have a lot to offer, but Stonehenge [] in particular is a good choice if you are interested in stone circles. In Avebury one can get closer to the stones than in Stonehenge but both sites are fascinating.
A car is the best way to get around that part of the country, especially when combining several sites.
Coach tours with various routes are available from London, and for a more personalized experience choose a driver-guided tour allowing you to pick just the sites you want. For example: Avebury and Stonehenge .
And for archaeology enthusiasts, their are special interest tours available such as Archeology Tour of Wessex 
Driver-guided tours from Bath can also be arranged on request.
For train travel, the official website for timetable is [www.nationalrail.co.uk]