As I've learned in this article written by 
Sorry, I didn't know. I am not a skateboarder after all.
My son is, though. Yesterday we spent the afternoon at the Urban Jam event in Ljubljana, Slovenia.
I only made one photo and this turned out quite well.
Ramps, pump tracks, jumps outside with permanent indoors skatepark, this is the Urban Roof area.
Sorry that I can't find any fresh photos from the event. This one is from setting the tent and the ramp prior to the event.
Source: event's Facebbok page
I do have a video of my son rollerblading on the ramp. I will upload it in the following days.
He was very surprised at how slippery the ramp was. Not at all like the firm grip of concrete or wooden ramps.
The ramp is produced and set up by the Flow Ramps, a group of Slovenian skating enthusiasts.
Flow Ramps is a portable urban sports platform. With services ranging from skateboarding and BMX workshops for complete beginners to big crowd demo shows with professional athletes, Flow Ramps comprises of highly competent and motivated staff, innovative programmes and services, premium quality equipment and international experiences.
So it was on Saturday, a aday earlier, that we somehow celebrated the Go Skateboarding Day :)
Better and better