Mingle with the most extravagant handlebar moustaches in Britain, pay your respects at the dog cemetery in Hyde Park, visit a Masonic temple, take trapeze lessons in a former power station, pray in a floating church, sail on a disused reservoir, discover the stone from which Arthur drew Excalibur, admire the sacred penis of a pharaoh, take aim on the City's last bowling green, go stargazing at Greenwich Observatory, examine a rare cucumber straightener,...