The gutter is built into the roof structure itself as a trough see illustration below.
Gutters built into roof.
Perhaps the rarest form of gutters on homes and commercial building structures are built in gutter systems.
I always try to encourage preserving original elements even though it might be easier to eliminate the old method for something new and inexpensive.
Eaves trough gutters may project forward from the lower roof edge shown in the sketch below or they may be virtually hidden from view from ground level when they are built into the slope of the roof.
Integral gutter eaves trough gutter built in gutter.
Built in gutter systems are actually built into the cornice structure and drain through internal or external leaders.
These systems are integrated into the design of the roofing structure.
Instead of hacking off a structurally sound or easily made sound eaves trough or integral gutter that is built into the roof surface you can just roof over it.
Built in gutter gutters.
Built in gutters the unseen roof drainage system was specifically chosen to be installed when the home was built thus is part of the original historic character.
Dating back to the 18th century yankee gutters consist of a v or u shaped wooden trough lined with metal usually copper or terne coated steel that directs water away from the house.
They are not readily visible from the ground further lending to the mystery of their design and function.
If the integral gutter is a nearly flat extension out over the roof edge also forming a soffit i d think about leaving the built in or integral gutter system in place removing any.