  MWC 297 is a young massive nearby B[e] star. The central star has a large
projected rotational velocity of 350 km/s. Despite the wealth of published
observations, the nature of this object and its dust-rich surroundings is not
well understood. With the present paper, we shed light on the geometrical
structure of the circumstellar matter which produces the near- to mid-infrared
flux excess, and construct an overall image of the source's appearance and
evolutionary status. The H-, K- and N-band brightness distribution of MWC 297
is probed with the ESO interferometric spectrographs AMBER and MIDI. We have
obtained visibility measurements on 3 AMBER and 12 MIDI baselines, covering a
wide range of spatial frequencies. We have reconstructed the brightness
distribution in H, K and N with a geometric model consisting of three Gaussian
disks with different extent and brightness temperature. This model can account
for the entire near- to mid-IR emission of MWC 297. The near- and mid-IR
emission, including the silicate emission at 10 micron, emanates from a very
compact region (FWHM < 1.5 AU) around the central star. We argue that the
circumstellar matter in the MWC 297 system is organized in a disk, seen under
moderate (i < 40 deg) inclination. The disk displays no inner emission-free gap
at the resolution of our interferometric data. The low inclination of the disk
implies that the actual rotational velocity of the star exceeds its critical
velocity. We discuss the impact of this result in terms of the formation of
high-mass stars, and the main-sequence evolution of classical Be stars.
