Placed at the base of a wall in a small green area alongside one of the many bridges crossing this intricate network of canals, this cache has space for several trackables or whatever else you may want to stick in there! You overlook one of the main junctions of this canal that was so hugely influential in the development of Birmingham's industry, adn the UK as a whole.
Start with the 'Malt House' food outlet on your right, and cross the bridge directly in front of you. Turn left down the ramp. Follow this towpath under the first bridge (~15 metres), and take the ramp on your right up the next footbridge (another ~15m). Cross the bridge and directly ahead is greenery and the 'Canal Walks 70' post. Located in these bushes, as per the hint.
Container is a small clear plastic tupperware box with a pale green 'Geocache' label. Approx dimensions 6cm x 6cm x 5cm.
Check out the history of the canal here: http://en.wikipedia.org/wiki/BCN_Main_Line