Attica Junction is an interesting and safe place to watch trains. Located just west of the Willard Yard, you can see the CSX (formerly, B&O) double mainlines (the same that run through Fostoria to the west and Greenwich to the east) and double mainline NS tracks. The NS tracks lead to Bellevue Yard to the north and to Marion, Delaware and Columbus to the south.
Attica Junction is located on Route 4 about 2 miles north of Rt 224, which runs through the small village of Attica. About 30 miles east of Fostoria, Attica Junction is a good place to see more NS trains than you might see in Fostoria, especially in the afternoons. To get to the junction (diamond) itself, go north on Rt 4 off of Rt 224 in Attica. Drive about 2 miles and cross over the CSX mainlines and immediately turn to the right (east) on the stone service road. You'll see the NS mainlines and the diamond to the right. Park away from the diamond and no one should bother you.
Attica Junction is nice early in the morning. Sitting virtually in the middle of corn fields, the sun rises are spectacular! Almost all trains that pass through Fostoria (except those that either turn south to Columbus or north to Toledo) will go through the junction. I have found the NS traffic is higher here, at least in the late mornings and afternoons.