Where am I?- No Pic you'll have to get your brain working

OUT OF HOURS WHERE AM I ?
1

I can’t give you a picture for this one as it’ll give it away.

I’m about to use a civil engineering project opened by Desmond Plummer in the 1960’s.

There’s a plaque which is clearly visible from the road.

But where is it?

2

blackwall tunnel

3

the sothern blackwell tunnel

4

Yes both right, well done eagle eyes.