Mt. Marathon is historic in Seward! Go during Fourth of July to watch the Mt. Marathon race. It's so exciting and intense! The kids race is even crazy!
Hike up the Jeep Trail - it starts out quite steep and then evens out. Cut over then to the hiking trail to go all the way to the top. Great views up there and along the way. Trail gets pretty nasty when it's wet out to beware.
The Mt. Marathon race is a true spectacle though and there is a huge party in town for it - its like the event of the year (or at least of the summer!)