Call them '60s relics or hippy home accessories, lava lamps have been casting their dim but groovy light on interiors for half a century, having hit British shelves 50 years ago on Tuesday.
A British company began marketing their original creation as an "exotic conversation piece" in 1963. Since then, millions of models of the much-copied invention have been sold worldwide.
The design was created by British inventor Edward Craven-Walker, who was inspired by an odd-looking liquid-filled egg timer he saw in a pub in southwest Britain.
"Everything was getting a little bit psychedelic," says Christine Baehr, the second of Craven-Walker's four wives. "There was Carnaby Street and The Beatles and things launching into space and he thought it was quite funky and might be something to launch into."