"Canthans with little spare time often say they are "busy as a Seitung Harbormaster". At least, in polite company."
Known also as Shing Jea Island, Seitung Province used to be the tutorial island for those who started characters in Guild Wars: Factions. A lot has changed in Cantha since the days of Factions and the environment in Seijtung Province is sometimes unrecognizable from the first game. However, there are some key locations you can find that will give you a peak into that classic Guild Wars nostalgia you may be looking for.
Shing Jea Monastery
Shing Jea Monastery has changed into something unrecognizable, but if you look carefully, you will be able to see three locations that coincide with each other between games. I recommend that you look for the long bell in both games to get your bearings. Although they are on different altitudes, I'm confident that it is the same bell. If you then use the bell as your guide, you can turn around to see the tunnel and bridge that lead to the training grounds. To the right of that tunnel is a familiar garden that overlooks the Shing Jea bay.
Zen Daijun Temple
Zen Daijun Outpost
Zen Daijun Temple is one of the easier places to pinpoint locations between games. Take note that the Temple differs from the outpost you see in Factions. The outpost can be found in Guild Wars 2 as the Derelict Temple point of interest. If you're looking to compare between the two games yourself, simply stand in the middle of the Zen Daijun Temple and note the south western bridge for each. You can also spot a familiar waterfall and bridge in the distance.
Another easy place to find a great view between the games, with the added bonus of having the lighthouse both games feature just outside of the location. My advice for finding the best place to start your comparison is to enter the walls that house the bell inside. In Factions, this is in the outpost labeled Zen Daijun; in Guild Wars 2 it is the point of interest labeled Derelict Temple. If you head north, you will find the gate leading towards the view of the lighthouse. The terrain leading to this view is very similar so it shouldn't be difficult to draw comparisons over a long plot of that land.
Although it may seem difficult at first to find similar locations here, Seitung Harbor hasn't change as much as its neighboring villages. There is a waist-level wall with ceramic roof tiles against the cliff separating the marketplace from the harbor. This wall is exactly the same between the two games, so putting your character against it will give you a great place to compare the two locations.