7 of 12Image
The actual labs where Bardeen, Brattain and Shockley invented the transistor in 1947 are some way north of here, but this is much more in keeping with the sightseeing ethos. It's a 60-foot water tower, erected during the building of new labs in 1961, in the shape of a giant three-legged transistor. If an Intel quad-core Xeon was built with transistors that size, it would be around 150km per side. In other words, it would cover an area bounded by London, Bristol, Birmingham and Peterborough.
Real-life visiting potential: 8/10. (Would be 10/10 for the entire Xeon).