Inner Tay Estuary viridis" - a species normally found only in north-eastern North America. Scottish Natural Heritage has commissioned and published habitat survey reports for the Inner Tay Estuary. Public roads run within a few hundred metres of the both north and south shores providing easy access to view the estuary and its wildlife, though car parking is limited in many places: (south shore) Wormit, Balmerino, Newburgh, Elcho Castle; (north bank) Riverside Drive in Dundee by the railway bridge, Invergowrie, Kingoodie, Port Allen, Powgavie, Cairnie Pier; (in Perth) from both banks, the bridges, Moncreiffe Island; (in Bridge of Earn) the bridge. The minor
Tay Bridge disaster anomalously high because of peculiarities of the site (one of the highest points on the Wirral.<ref name="The Wirral Hundred/The Wirral Peninsula"></ref>): a wind pressure of would overturn railway carriages and such events were a rarity. (To give a subsequent, well documented example, in 1903 a stationary train "was" overturned on the Levens viaduct but this was by a 'terrific gale' measured at Barrow in Furness to have an average velocity of , estimated to be gusting up to .) A new double-track Tay Bridge was built by the NBR, designed by Barlow and built by William Arrol & Co. of