Underwater hotels have been growing in popularity in recent years, with one currently under construction in Dubai. However, floating luxury homes with a floor below sea level for underwater viewing are something totally new to me. That’s the idea behind the Jelly-fish 45 dwelling designed by Giancarlo Zema. The five-storey dwelling is 10 metres high with a diameter of over 15 metres at its maximum, and it can accommodate 6 to 8 people. You want one, did you say? That’ll be $2.5 million, please.