The Firth of Forth was not "built" - it was created by a glacier in the last ice age. A firth is the lowland Scots word for an inlet from the sea, much the same as the Scandinavian word 'fjord' - in this case the estuary of the River Forth. I think you probably mean "When was the Forth (Rail) Bridge built?", and the answer to that is between 1883 & 1890. It was joined by a parallel road bridge in 1964. The railway bridge - still a hugely impressive structure - was the engineering wonder of its age, though it was achieved at the cost of many workers' lives. It is seen in a number of old films - most famously in both the 1935 & 1959 versions of "The 39 Steps".
Edinburgh, the capital of Scotland, is on the Firth of Forth.
The Antonine Wall is between Firth of Forth and Firth of Clyde.
The Forth road and rail bridges span the Firth of Forth, which is the estuary of the River Forth in Scotland near the city of Edinburgh.
Edinburgh
The Antonine Wall is in Scotland, between the Firth of Forth and the Firth of Clyde.
Edinburgh.
The Antonine Wall is in Scotland, between the Firth of Forth and the Firth of Clyde.
Scotland on the banks of the Firth of Forth
There are two bridges over the Firth of Forth. The rail bridge and the road bridge.
The Firth of Forth is the tidal body of water where the River Forth meets the North Sea on the East coast of Scotland. The capital city of Edinburgh, and its dock of Leith, astrides the Firth to the south, whilst the Kingdom of Fife lies to the north.
About 400 miles
Yes he did go North of the Forth, all the way to Inverness.