Ya, make sure you put a lever on the bridge (drawbridges are best rather than disappearing bridges as they act like a wall when up), and put the lever by a meeting area inside.
This is the tileset I use
it is actually pretty simple, and I preferred it over the graphics stuff as it didn't corrupt the text in the game
the double stacked + sign is paved, smoothed, or tiled floor
the random colored .,'` stuff and black background is rough ground, round solid things are boulders
,'% etc with a color around it is rough walls
the smooth stuff is build walls or smoothed natural walls
faint . shows empty space with a floor 1 z level down
^ are stonefall traps
the smooth border around double + are bridges
smiley faces are dwarves, helmet are dwarf soldiers. color says what their profession is
Trees are tree shaped, squigly y are saplings, " are bushes
# is are floor grates, the thick vertical line with a think horizontal line is a wall grate (picture 2)
double ~ is surface water if blue, lava if red (same for numbers)
!! are cages
smooth wall looking things with T type ends are raised bridges (top of pic 2 for example)
The thick + shaped things are fortifications
+ are doors
The white man shaped outlines are statues (pic 4)
the o with a ` above are levers
the grey double barrel shaped things are pumps
notched right angle triangles are stairs going up or down, X are stairs going up and down, smooth right angle triangles are ramps (eg bottom of pic 5)
g is goblin (red outlines mean dead ones, color of letter indicates type of soldier), C is cow, d is dog, etc
the male symbol (shield and spear) are bags
% are prepared meals
brown double ~ are farm fields thick horizontal bars are planted fields
X surrounded by brown are bins
brown = is wood
= with three lines are bars