It's a coffee shop on a bike and it is called the Beehive Cafe!
I stopped to take a quick pic and asked the owner if he had a webpage. He said he has a facebook page called Beehive Cafe.
From facebook I can see they also sell pastries as well as coffee and they offer honey to sweeten your tea.
It is on the Rock Road at Booterstown Park and serves tea & coffee every weekday morning between 7.30am and 10.30am.
What a clever idea. I do hope this endeavour works out for this ingenious entrepreneur.
