■ADRIANA    VON HAGENPLANNING,   SETTLEMENT
As  Tahuantinsuyu   expanded,   the Incas   launched    a   massive construction    program,
building     works   of  infrastructure  as  well    as  new     settlements.    The     new
infrastructure   included    an  extensive  road     network,    innumerable     agricultural
terraces,   and wide-ranging    irrigation  systems.    The Incas   spanned canyons and
rivers  with    ingenious   suspension  bridges,    a   technology  hitherto    unknown to  the
Europeans.  In  conjunction with    works   of  infrastructure, the Inca    built   fortresses,
tambos   (way    stations),  administrative  centers,   royal    estates,    and     religious
sanctuaries.    At  tambos  and administrative  centers,    in  particular, they    built   large
storage  facilities  holding     a   variety     of  goods   from    food,   to  clothing,   and
weaponry,   among   other   things, that    provided    for the needs   of  the traveling   Inca
ruler   and his entourage,  the army    on  the move,   the state   religion,   and the local
population.
Several  Spanish     chronicles  suggest     that    Inca    planners    made    clay    models  to
visualize   their   concept of  new settlements.    In  developing  their   concepts    the Incas
took    into    account a   number  of  factors:    location,   function,   terrain,    landscape,  and
orientation,    among   others. Most    settlements were    strategically   located along   an
Inca    road.   Many    were    built   on  vacant  land;   in  other   cases   the Inca    adopted and
transformed  existing    settlements.    Way     stations    were    typically   spaced  about   a
day’s    travel  apart;  administrative  centers     appear  to  have    been    placed  near
concentrations  of  local   ethnic  groups; most    royal   estates were    focused on  the
Cuzco   heartland;  sanctuaries,    devoted almost  exclusively to  religious   activities,
were    state   installations   at  recognized  Andean  holy    places.