No, I'd never heard of it either, but apparently lighthouse bagging is becoming increasingly popular. It's a bit like trainspotting but on a slightly grander scale.
The craze of lighthouse bagging has recently made the news, with the revelation that it's one of
Princess Anne's favourite pasttimes.
The unusual hobby, called pharology in technical jargon, involves touring remote regions of coastline in an effort to visit as many lighthouses as possible.
Through her role as patron of the
Northern Lighthouse Board (NLB) - Scotland's national lighthouse authority - the Princess has been able to bag more than 80 lighthouses under the Board's ownership.
According to Roger Lockwood, Chief Executive of the NLB, the Princess takes a very keen interest in how the lights operate.
"She must have visited over 80 with us and takes her role as patron very seriously.
"It is not just about ticking off another light on the list – she also likes to see the places and conditions in which the technicians have to work.
"The Princess has done all the major lights now and it will not be easy to do them all because there are many that are scattered all over the place. But it will be a remarkable feat if the Princess ticks them all off. Other than some of our technicians I doubt if anybody else has been to all of them."
Apparently the Princess is not alone in her quest to visit all of Scotland's 209 lights.
"We see a lot of these anoraks, sorry, pharologists, who show a lot of interest in the lights. They are a far more sensible lot than the twitchers and the trainspotters," said Mr Lockwood.
"Generally, the more remote the lighthouses are, the happier they are to have visited them. Some have great difficulty visiting these far-flung corners of the Hebrides, and Orkney and Shetland. That adds to the appeal."
Touring remote Scottish Islands, enjoying their uninhabited natural beauty, breathing fresh air and looking at a few lighthouses. That's my kind of hobby!