Dundalk is a collection of neighborhoods. Old Dundalk, St. Helena, Logan, Watersedge, Turners station, Graceland park, Berkshire, Eastfield, West Inverness, Grey Charles, Charlesmont, Colgate, and Eastwood. Some have gotten better since the 80's, and some worse. The addicts coming down from the city and sex offenders have moved into Dundalk. When I was a child in the 90's, we would ride our bikes all over as young as 10\11yrs old. Now, I won't let my son leave the yard, you need to be careful, the sketchy people stand out like sore thumbs but where they are you don't know
I'm not super familiar with the county, so maybe someone else can chime in, but I've never really gotten a bad vibe from anywhere in Dundalk. There's definitely drugs and homelessness in some areas, especially around Dundalk Ave but that's about the extent of what I know about the area.
