This geological phenomenon came about, as molten rocks (lava) were cooling off. According to a legend, however, the Giant's Causeway was created by Giant Finn McCool as he wanted to travel  over to Scotland without getting wet feet. Hence the name. 

The Giant's Causeway is a National Trust property 
 
 
 

We also visited Londonderry's inner city (town walls partly accessible through ramps) which is nice, but very steep with narrow streets and therefore a bit difficult for wheelchair users to get around. 
If your able-bodied travel mates set off to surround the city centre on its town walls, calculate about an hour's time for this. 

The tourist brochure did not contain any information on disabled access. There didn't seem to be that many disabled parking spaces either. After being misguided by a stupidly-placed sign apparently pointing to a closed car-park, I found an accessible loo in that shopping center containing the Marks & Spencer department store. Might not be open 24 hours a day, but was open on Sunday. 

Conclusion: Looks like the city could use some improvements in accessibility for the disabled. It may well be, though, that there still exist more urgent problems to solve in this city. 

For an in-depth discussion of the "Bloody Sunday" event taking place in Londonderry and its significance for the conflict  in Northern Ireland, I suggest visiting the CAIN Project Website. 
 
  

• The National Trust, an organisation devoting itself to the conservation of important historic and natural places throughout the UK. The website contains useful information on all properties managed by the National Trust, including access for the disabled.

• Causeway Page at the Northern Irish Tourist website

• Views of Northern Ireland -- pictures and information not just on the Giant's Causeway, but also many other scenic places in the region

• Virtual Tour of Northern Ireland

• Bushmills Distillery -- famous distillery of Irish Whiskey

• Portrush -- the biggest resort on the Antrim coastline. 

• CAIN Project. This acronym stands for Conflict Archive on the Internet. The conflict in question being the Northern Ireland one, of course. For everyone interested in thorough, balanced information on a scientific level, this is an inevitable website.

Accessibility Information

Considering the rugged environment, disabled access to this major tourist destination is very good indeed. I was both surprised and impressed. The visitors centre and the adjacent parking lot is completely accessible to wheelchair users. There's a couple of ramps inside and outside which  might be a bit steep for people with limited armpower, but there'll always be someone around to give a hand. Fully accessible loo; the key is to be obtained from the centre's main souvenir counter. 
 
The "Causeway coaster" has a special wheelchair compartment in the back. The ride is free of charge for disabled people. There are these typical mounts on the bus floor to lock and buckle up wheelchairs. I didn't see any of the straps though and wasn't buckled up either. However, due to the steepness of the terrain, this might be advisable for people who have difficulties preventing themselves from  moving or tipping over. 

Down on the coastal  level, there is one footpath along the coastline which wheelchair folks can use for the first 200 meters or so until it bends and goes straight uphill. Except for the paved driveway, all other trails are pretty much impossible, including the one leading from the visitor's centre to the nearby clifftop.  

The driveway itself looks manageable for manual wheelchairs, also in its steep upper part. It will give you quite a nice workout! 
 

 
Accommodation  
We stayed at the Valley View B&B in Bushmills, approximately 6 miles south of the Giant's Causeway, and I whole-heartedly recommend this place  to wheelchair users and able-bodied travellers alike! There is one fully accessible, very tastefully furnished en-suite bedroom (wheel-in shower/shower seat). Prices p/p/night between 15 and 22 pounds, including a very good breakfast. The proprietors are exceptionally hospitable and truly enjoy accomodating their guests. 

According to the accommodation guide for the Antrim Coast & Glens, there are several other places suitable for wheelchairs in the area.  The brochure is called "Where To Stay" and can be obtained at any Tourist Information Center in Northern Ireland. Take my advice and try the Valley View B&B first!