  We report on a multi-wavelength (IR to cm) and multi-resolution (1 mas to 20
arcsec) exploration of high-mass star formation regions in the Galactic plane,
at longitudes observable from the Southern Hemisphere. Our source sample was
originally identified through methanol masers in the Galactic plane, which
exclusively trace high-mass star-forming regions. (Sub)millimetre continuum and
molecular line observations were carried out with SEST/SIMBA, JCMT/SCUBA and
ATNF/Mopra mm-wave telescopes and have allowed us to identify massive ($>20$
M$_{\odot}$) and luminous ($>10^3$ L$_{\odot}$) clumps in each star-forming
region. We have also constrained the SED with additional archival IR data, the
physical conditions ($T_{dust}$, $L$, $M$) and the chemical composition of each
massive clump. Several types of objects were characterised based on the
$L_{submm}/L_{bol}$ ratio, the dust temperature and the molecular line
properties, ranging from class 0-like YSO clusters ($L_{sub}/L_{bol}\sim1%$,
T=30 K) to hot molecular clumps ($L_{sub}/L_{bol}\sim0.1%$, $T=40-200$ K).
Preliminary high-angular resolution observations for a subset of the sample
with the ATNF/ATCA at 3 mm, the VLA at 15, 22 and 43 GHz and Gemini in MIR have
revealed that several (proto)stellar objects are embedded in the massive
clumps: massive protostars, hot cores and hyper-compact HII regions. We have
thus identified protoclusters of massive YSOs, which are the precursors of the
OB associations. This sample of Southern Hemisphere star-forming regions will
be extremely valuable for the scientific preparation of the ALMA and HSO
observations.
