Simplify the following text for a Grade 8 native English-speaking person.
Original: Dumfries , meaning either fort or ridge of the thicket , is a former royal burgh and town within the Dumfries and Galloway council area of Scotland and is situated close to the Solway Firth , near the mouth of the River Nith .
Simplified: Dumfries ( according to one theory from the ) is a market town and former royal burgh within the Dumfries and Galloway council area of Scotland . It is near the mouth of the River Nith into the Solway Firth .