We announce the classification of two related classes of flag-transitive geometries. There is an infinite family of such geometries, related to the nonsplit extensions
3
[
n
2
]
2
⋅
Sp
2
n
(
2
)
{3^{[\begin {array}{*{20}{c}} n \\ 2 \\ \end {array} ]}}^2 \cdot {\text {Sp}}_{2n}(2)
, and twelve sporadic examples coming from the simple groups
M
2
2
{M_22}
,
M
2
3
{M_23}
,
M
2
4
{M_24}
, He,
C
o
1
Co_{1}
,
C
o
2
Co_{2}
,
J
4
{J_4}
, BM, M and the nonsplit extensions
3
⋅
M
2
2
3 \cdot {M_22}
,
3
23
⋅
C
o
2
{3^{23}} \cdot Co_{2}
, and
3
4371
⋅
B
M
{3^{4371}} \cdot BM
.