all four so far

I think I went round these these in the wrong order. The Innocent (top right, nonlocals) it the most impressive tunnel length-wise, the tunnel I'm most familiar with and the first one I found out about. The Colinton/Spylaw tunnel (TL) has the best echo and (despite being a pain in the arse to get at on a road bike if it's rained at any point in the past three weeks) has nice small bricks, making it seem bigger and longer than it is, especially when it's excitingly curved so that there's only a small point where both ends are visible. Slightly irritating that I was there at the wrong time to be able to get blown-out sunlight highlights at the end but the large amount of shade-providing water-sucking-up treeness either side of the tunnel and all along the upper bit of the Water of Leith walkway are generally a good thing. In comparison, the Trinity tunnel (BR) is relatively dull; quite short and straight and somehow too circular in section, though the straightness of the path on the north approach from Granton is such that when the trees further along obscure the tunnel's brickwork one can see straight through to the brightly-lit path on the other side without seeing anything in between to signify the tunnel's presence, which is pleasing. Along with the nasty-looking orange gunk seeping from the walls. Although pleasing for the chance it offers to miss out the Broughton Road/Rodney Street/Canonmills/Eyre Place junction with its many road-crevasses and frequent driver-idiocy the Rodney Street tunnel (BL) is far too well-lit, short and wide to be particularly tunnelly and all exits from the park at the south lead to cobblestreets but it's a nice thing to have and it's nice to vainly hope that one day the very-nearly-contiguous Scotland Street tunnel might one day provide a means of getting all the way to Waverley without having to deal with any traffic on the way.