An example of silliness is the recently established Waterville Park. On two sides it is surrounded by a large fence with gates that are locked at night. The third side is effectively blocked off by a combination of the M3 motorway (still under construction) and the Tolka River. However, the fourth side is completely open and anyone can enter at any time. Although there are signs up telling people about the park opening hours there there is no physical barrier to stop people entering at night to vandalise the plans and/or hold a drinking party.
This means that the locked gates are of no use in keeping the park safe, but at the same time they effectively stop people from walking through the park as a more pleasant alternative to going on the road around it.
Many of the residents of the Waterville estate would use this route as a short cut to get to the school or Hospital that are beside the park. I myself can sometimes incorporate this park into my route to work. In theory the gates should not be opened until 10am, but often they are opened much earlier - the trouble is that I don't know until I get to the gate whether or not it is going to be open. If it is locked I need to retrace my steps because as you can see from the picture it is not really feasible for me to climb over the gate while carrying my bike.
I think that the council could save themselves a lot of money and make the park a more useful amenity if they simply left the gates open all the time. The increased number of socially responsible people walking/cycling through the park would also make the park a less attractive venue for teenage drinking parties.