Gasholders aren't really all that useful in today's society. Originally used to store large amounts of gas, nowadays many of them lie empty, the threat of demolition looming. But while some people see gasholders as eyesores, another section of society view them as monuments to a bygone era.
This has led to some gasholders becoming listed, and even cleverly repurposed. Whether you like them or not, it's hard to argue with the epic nature of these skeletal behemoths.