Tell me where all past years are

According to proper boffins such as Stephen Hawkings time travel isn't necessarily impossible but the mere fact that we've never met any time travellers coming back to check out the 21st century probably means we don't invent time travel. I can't remember where I first heard it but isn't it a great theory that this is what UFOs are? The most common occupants of UFOs are Greys and it's easy to see them as what humans might evolve into in a few thousand years. Big brains on spindly, hairless little bodies. The result of a species separated by technology from a world polluted by all the crap we're constantly hearing about and maybe a few nuclear wars as well? Why don't they stop and say hello? They've probably got a rule along the lines of the prime directive in Star Trek or they're worried about stepping on butterflies like in the Ray Bradbury story.

Despite the unlikeliness of me ever hitching a ride on a time machine I have given some thought to my top destinations for a time holiday:

Ancient Rome
At some point in the reign of Hadrian, pop along to see a show at the Colosseum maybe? Check out a few second hand scroll shops, try and pick up copies of Sulla's memoirs and Claudius' Etruscan dictionary.

Monterey Pop Festival
It may seem trivial but I'd really like to see Jimi Hendrix play. Maybe this is too iconic a performance, it might be better to see him in a small club in London. Or Bob Dylan at the Manchester Free Trade Hall.

Stonehenge
Round about 3000 BC. To see what it was (is) really for. And to see it in pristine condition.

The Crucifixion
And the resurrection. Which I don't believe in, but just to make sure.

Elizabethan London
To see the medieval city in all its spiky and highly flammable glory. See Shakespeare & Co putting on a play. Eat roast boar at one of those frost fairs on the Thames. Go for a gloat at traitors gate.

Late Cretaceous
Dinosaurs