So to clarify the title, Fundy National Park is beside Alma. It is definitely worth seeing. But the Parkway is near St Martin's and it is really spectacular - probably not as well known, as it is newer.
If you have been on the Cabot Trail in Nova Scotia you have had a taste of what this is like. Cabot however is a roadway meant to be travelled by everyone, this parkway is not. It twists and turns over the Bay of Fundy, sometimes you have to slow to 30 km/hour. There are a huge number of lookouts and lots of trails plus beaches. They have an excellent flower pot too. The Parkway climbs and climbs from entry to where it ends 16 km later. The last few kilometres are quite new and really high and it is a bit scary to go around some of those curves, but definitely worth it. The views are spectacular. There is an interpretive centre at the 9 km mark, worth visiting too, plus a suspension bridge. Just after the centre there is a place where they have cut thru the rock, unbelievable to see. This is one of Canada's most spectacular tourist attractions, it is too bad it is not better known and a bit more accessible. (The roads to St Martin's could give you car sickness they are so uneven - and slow!)