Glentress is considered the best mountain bike trail center in the UK. The Scottish mountain bike mecca is located in the Tweed Valley, less than an hour south of Edinburgh. Glentress offers trails for everyone. I did the black route first, an epic singletrack trail with long ascents and fun descents. Then, I did the blue run and the freeride section: all smooth with lots of berms and jumps. I would have done as well the red route, if I just had had the legs for another 16 km. In summary, I spent an awesome day on the Glentress trails with 46 km and 1200 m elevation gain.
Innerleithen, which is about 7 miles south of Glentress, has only one red XC route, but several thrilling downhill runs. I did Innerleithen XC trail in the morning and after one or two miles it started to rain. The smooth dark rocks on the trail become very slippery when wet. I had to realize that in a sharp turn when my front wheel sled and I had to use my knee to decelerate… Apart from that, the trail is nice and towards the end serious fun descending.